We are investigating the high resolution structure of native and variant B. lentus subtilisin. We have collected data to 0.85 E resolution from cryocooled crystals of the native enzyme at pH 5.9 and pH 8.8. We have not yet been able to determine the limit of the diffraction. Data were detected at the current experimental limit of 0.75 E resolution. We would like to explore the limit of the resolution and to extend this analysis to variants that have displayed even higher diffraction than the native enzyme under comparable room temperature conditions.